Abstract:

An electronic-data authentication method is for authenticating electronic
data provided by a virtual person anonymously used on a network,
performed by a virtual-person management system including a user
terminal, a user management device, and a virtual-person management
device. The method includes receiving, by the virtual-person management
device, the electronic data, a first electronic signature generated by
encrypting the electronic data with a first signature-creation key, and
an virtual person ID for uniquely identifying the virtual person from the
user terminal; authenticating, by the user management device, the first
electronic signature received at the receiving by using a first
signature-authentication key corresponding to the first
signature-creation key; generating, by the virtual-person management
device, a second electronic signature by encrypting the electronic data
received at the receiving with a second signature-creation key issued for
the virtual person; and transmitting, by the virtual-person management
device, the second electronic signature to the user terminal.

Claims:

1. An electronic-data authentication method for authenticating electronic
data provided by a virtual person anonymously used on a network,
performed by a virtual-person management system including a user
terminal, a user management device, and a virtual-person management
device, the electronic-data authentication method comprising:receiving,
by the virtual-person management device, the electronic data, a first
electronic signature generated by encrypting the electronic data with a
first signature-creation key, and an virtual person ID for uniquely
identifying the virtual person from the user terminal;authenticating, by
the user management device, the first electronic signature received at
the receiving by using a first signature-authentication key corresponding
to the first signature-creation key;generating, by the virtual-person
management device, a second electronic signature by encrypting the
electronic data received at the receiving with a second
signature-creation key issued for the virtual person; andtransmitting, by
the virtual-person management device, the second electronic signature to
the user terminal.

2. The electronic-data authentication method according to claim 1, further
comprising requesting, by the virtual-person management device, a
predetermined organization to issue an electronic certificate for
authenticating a second signature-authentication key corresponding to the
second signature-creation key thereby acquiring the electronic
certificate, whereinthe transmitting includes transmitting the electronic
certificate acquired at the requesting as well as the second electronic
signature.

3. The electronic-data authentication method according to claim 1, further
comprising issuing, by the virtual-person management device, an
electronic certificate for authenticating a second
signature-authentication key corresponding to the second
signature-creation key, whereinthe transmitting includes transmitting the
electronic certificate issued at the issuing as well as the second
electronic signature.

4. The electronic-data authentication method according to claim 2, wherein
the second signature-creation key is identical to the second
signature-authentication key.

5. The electronic-data authentication method according to claim 3, wherein
the second signature-creation key is identical to the second
signature-authentication key.

6. The electronic-data authentication method according to claim 1, wherein
the first signature-creation key is identical to the first
signature-authentication key.

7. The electronic-data authentication method according to claim 1, wherein
the authenticating includesacquiring, by using the virtual person ID
received at the receiving, the first signature-authentication key that is
previously stored in association with the virtual person ID,
anddetermining that the first electronic signature is authentic if a
digest generated by decrypting the first electronic signature with the
first signature-authentication key is identical to a digest generated by
hashing the electronic data received at the receiving by using a hash
function.

8. An electronic-data authentication method for authenticating electronic
data provided by a virtual person anonymously used on a network,
performed by a virtual-person management system including a user
terminal, a user management device, a virtual-person management device,
and a service providing device, the electronic-data authentication method
comprising:receiving, by the service providing device, the electronic
data, a first electronic signature generated by encrypting the electronic
data with a first signature-creation key, and an virtual person ID for
uniquely identifying the virtual person from the user terminal;receiving,
by the virtual-person management device, the electronic data, the first
electronic signature, the virtual person ID from the service providing
device,authenticating, by the user management device, the first
electronic signature by using a first signature-authentication key
corresponding to the first signature-creation key;generating, by the
virtual-person management device, a second electronic signature by
encrypting the electronic data received by the virtual-person management
device with a second signature-creation key issued for the virtual
person; andtransmitting, by the virtual-person management device, the
second electronic signature to the service providing device.

9. An electronic data authenticating system for authenticating electronic
data provided by a virtual person anonymously used on a network,
comprising:a user terminal;a virtual-person management device that
includes a receiving unit configured to receive the electronic data, a
first electronic signature generated by encrypting the electronic data
with a first signature-creation key, and an virtual person ID for
uniquely identifying the virtual person from the user terminal; anda user
management device that includes an authenticating unit configured to
authenticate the first electronic signature received by the
virtual-person management device by using a first
signature-authentication key corresponding to the first
signature-creation key, whereinthe virtual-person management device
further includes an generating unit configured to generate a second
electronic signature by encrypting the received electronic data with a
second signature-creation key issued for the virtual person, and a
transmitting unit configured to transmit the second electronic signature
to the user terminal.

Description:

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001]This application is a continuation of PCT international application
Ser. No. PCT/JP2008/051937 filed on Feb. 6, 2008 which designates the
United States, incorporated herein by reference, and which claims the
benefit of priority from Japanese Patent Application No. 2007-094523,
filed on Mar. 30, 2007, the entire contents of which are incorporated
herein by reference.

FIELD

[0002]The embodiments discussed herein are directed to an electronic-data
authentication method, an electronic-data authentication program, and an
electronic-data authentication system that are useful for authenticating
electronic data provided by a virtual person anonymously used on a
network.

BACKGROUND

[0003]Conventionally, to prevent personal information of a user from
leaking to a third person, there is provided a system that allows the
user to anonymously engage in buying and selling a product or writing a
message on a bulletin board on the Internet. For example, Japanese
Laid-open Patent Publication No. 2002-123633 discloses a system in which
information indicating a correspondence relationship between a virtual
person anonymously used on a network and an actual person is registered
in a predetermined organization that has a confidentiality obligation, so
that the person can open a bank account, make credit settlement, deliver
or receive a product, and the like, as the virtual person. Furthermore,
Japanese Laid-open Patent Publication No. 2002-132148 discloses an
authentication method using an electronic signature with a public-key
encryption method.

[0004]The user uses the virtual person because anonymity of the virtual
person is attractive to the user. Specifically, the user can conceal
personal information of the user by using the virtual person. However, if
a conventional authentication method using an electronic signature is
employed for electronic data provided by the virtual person, a public key
of the user who is the owner of the virtual person is disclosed to the
public. Moreover, an electronic certificate for authenticating the public
key needs to be issued by a predetermined authentication organization.
Therefore, there is a possibility of leakage of information that can
identify the owner of the anonymous virtual person due to the presence of
the public key.

[0005]Furthermore, in a conventional system, because it is considered that
the virtual person is associated with the actual person, there is no
consideration for assignment of the virtual person to a third person.
However, as the user operates as the virtual person on the network, it is
possible that the virtual person itself obtains credibility and a
financial worth is found with respect to the credibility. For example,
assuming that the virtual person is assigned to a third person, in the
conventional authentication method using the electronic signature, each
time the owner of the virtual person is changed, a public key of a user
who is the current owner of the virtual person is changed to a public key
of a user who is a new owner of the virtual person. Therefore, because
the change of the public key is disclosed to outsiders, it is possible to
guess that the owner of the virtual person has been changed. As a result,
it is possible for a third person to analyze a difference in behavior
characteristics of the virtual person around the time when the owner is
changed, which can affect the credibility included in the financial worth
of the virtual person.

SUMMARY

[0006]According to an aspect of the invention, an electronic-data
authentication method for authenticating electronic data provided by a
virtual person anonymously used on a network, performed by a
virtual-person management system including a user terminal, a user
management device, and a virtual-person management device. The
electronic-data authentication method includes receiving, by the
virtual-person management device, the electronic data, a first electronic
signature generated by encrypting the electronic data with a first
signature-creation key, and an virtual person ID for uniquely identifying
the virtual person from the user terminal; authenticating, by the user
management device, the first electronic signature received at the
receiving by using a first signature-authentication key corresponding to
the first signature-creation key; generating, by the virtual-person
management device, a second electronic signature by encrypting the
electronic data received at the receiving with a second
signature-creation key issued for the virtual person; and transmitting,
by the virtual-person management device, the second electronic signature
to the user terminal.

[0007]According to another aspect of the invention, an electronic-data
authentication method for authenticating electronic data provided by a
virtual person anonymously used on a network, performed by a
virtual-person management system including a user terminal, a user
management device, a virtual-person management device, and a service
providing device. The electronic-data authentication method includes
receiving, by the service providing device, the electronic data, a first
electronic signature generated by encrypting the electronic data with a
first signature-creation key, and an virtual person ID for uniquely
identifying the virtual person from the user terminal; receiving, by the
virtual-person management device, the electronic data, the first
electronic signature, the virtual person ID from the service providing
device, authenticating, by the user management device, the first
electronic signature by using a first signature-authentication key
corresponding to the first signature-creation key; generating, by the
virtual-person management device, a second electronic signature by
encrypting the electronic data received by the virtual-person management
device with a second signature-creation key issued for the virtual
person; and transmitting, by the virtual-person management device, the
second electronic signature to the service providing device.

[0008]The object and advantages of the invention will be realized and
attained by means of the elements and combinations particularly pointed
out in the claims.

[0009]It is to be understood that both the foregoing general description
and the following detailed description are exemplary and explanatory and
are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF DRAWING(S)

[0010]FIG. 1 is a system block diagram of a virtual-person management
system;

[0011]FIG. 2 is a functional block diagram of a virtual-person management
device according to a first embodiment of the present invention;

[0012]FIG. 3 is a diagram of data formation of a virtual-person
information file;

[0013]FIG. 4 is a diagram for explaining a format example of a
virtual-person electronic certificate;

[0014]FIG. 5 is a diagram for explaining information set in main items
contained in the virtual-person electronic certificate;

[0015]FIG. 6 is a functional block diagram of a user management device
according to the first embodiment;

[0016]FIG. 7 is a diagram of data formation of a user information file;

[0017]FIG. 8 is a sequence chart for explaining an operation performed
when a virtual person ID is issued;

[0018]FIG. 9 is a sequence chart for explaining a key creation operation
performed by the virtual-person management device and the user management
device;

[0019]FIG. 10 is a sequence chart for explaining an example of an
operation performed when electronic data is authenticated;

[0020]FIG. 11 is a schematic diagram for explaining a first
electronic-signature generation operation performed by a user terminal A
as represented in FIG. 10;

[0021]FIG. 12 is a schematic diagram for explaining a first authentication
operation performed by a user management device A as represented in FIG.
10;

[0022]FIG. 13 is a schematic diagram for explaining a second
electronic-signature generation operation performed by the virtual-person
management device as represented in FIG. 10;

[0023]FIG. 14 is a schematic diagram for explaining a second
authentication operation performed by a user terminal B as represented in
FIG. 10;

[0024]FIG. 15 is a sequence chart for explaining an example of the
operation performed when the electronic data is authenticated;

[0025]FIG. 16 is a block diagram of a computer that executes an
electronic-data authentication program;

[0026]FIG. 17 is a functional block diagram of a virtual-person management
device according to a second embodiment of the present invention;

[0027]FIG. 18 is a diagram for explaining information set in the main
items contained in the virtual-person electronic certificate in the case
of a common-key encryption method;

[0028]FIG. 19 is a schematic diagram for explaining the second
authentication operation in the case of the common-key encryption method;

[0029]FIG. 20 is a schematic diagram for explaining the second
authentication operation performed by the virtual-person management
device as depicted in FIG. 19; and

[0030]FIG. 21 is a schematic diagram for explaining an
authentication-result notification information generation operation
performed by the virtual-person management device as depicted in FIG. 19.

DESCRIPTION OF EMBODIMENT(S)

[0031]Preferred embodiments of the present invention will now be described
in detail of an electronic-data authentication method, an electronic-data
authentication program, and an electronic-data authentication system with
reference to the accompanying drawings.

[a] First Embodiment

[0032]A configuration of a virtual-person management system 1 according to
a first embodiment of the present invention will be explained below. FIG.
1 is a system block diagram of the virtual-person management system 1. As
depicted in FIG. 1, the virtual-person management system 1 includes a
virtual-person management device 10, user management devices 20, user
terminals 30, and a service providing device 40. In the following
description, an explanation will be given for the virtual-person
management system 1 in which, for example, if a user terminal A provides
the service providing device 40 with electronic data generated by a
virtual person, a third person who has acquired the electronic data from
the service providing device 40 can confirm that the electronic data is
undoubtedly a product material generated by the virtual person, and
information for identifying an owner of the virtual person can be
prevented from being leaked to outsiders upon provision of the electronic
data. The electronic data generated by the virtual person corresponds to,
for example, contents data including document data such as an experience
note or a diary.

[0033]The virtual-person management device 10 manages information about a
virtual person anonymously used on a network. The user management device
20 manages information about an actual user who owns a virtual person.
The user management device 20 is arranged for each management company.
The management company ensures responsibility capacity of a virtual
person who is used by a user managed by the user management device 20
owned by the management company. The user terminal 30 is used by a user
who owns a virtual person. The service providing device 40 provides the
user terminal 30 with various types of services on the network. A service
provided to the user terminal 30 corresponds to, for example, shopping on
a network, a bulletin board, or an intermediary service for transaction
of various types of electronic data. A service provided by the service
providing device 40 can be used by both an actual person and a virtual
person.

[0034]A functional configuration of the virtual-person management device
10 according to the first embodiment will be explained below with
reference to FIG. 2. FIG. 2 is a functional block diagram of the
virtual-person management device 10 according to the first embodiment. As
depicted in FIG. 2, the virtual-person management device 10 includes a
control unit 11 that totally controls the virtual-person management
device 10 and a storage unit 12 in which a program used for an operation
performed by the control unit 11, various types of data such as a
virtual-person information file 121, and the like, are stored.

[0036]The virtual-person information management unit 111 manages virtual
person information stored in the virtual-person information file 121.
Data formation of the virtual-person information file 121 will be
explained below with reference to FIG. 3. FIG. 3 is a diagram of the data
formation of the virtual-person information file 121. The virtual-person
information file 121 contains, for example, a virtual person
identification (ID), a user-management device ID, a second
signature-creation key, a management-company responsibility-capacity
evaluated value, and a virtual-person responsibility-capacity evaluated
value as data items. An ID for uniquely identifying a virtual person is
stored in the virtual person ID. An ID for uniquely identifying a user
management device that manages information about a user who owns a
virtual person is stored in the user-management device ID.

[0037]A public key used for a third person to authenticate electronic data
provided to the service providing device 40 by a virtual person is stored
in the second signature-creation key contained in the virtual-person
information file 121. Although a public-key encryption method is employed
as an encryption method used for generating a second electronic signature
that will be explained later in the first embodiment, the encryption
method is not limited to the public-key encryption method. A common-key
encryption method (secret-key encryption method) can be employed as the
encryption method. An explanation will be given for an example in which
the common-key encryption method is employed as the encryption method for
generating the second electronic signature in a second embodiment of the
present invention.

[0038]A management-company responsibility-capacity evaluated value for
evaluating a level of a responsibility capacity of a management company
of the user management device 20 is stored in the management-company
responsibility-capacity evaluated value contained in the virtual-person
information file 121. A virtual-person responsibility-capacity evaluated
value for evaluating a level of a responsibility capacity of a virtual
person is stored in the virtual-person responsibility-capacity evaluated
value contained in the virtual-person information file 121.

[0039]The virtual-person information management unit 111 depicted in FIG.
2 creates the second signature-creation key (secret key) and a second
signature-authentication key (public key) as a pair of keys used for an
electronic signature of electronic data provided by a virtual person, and
stores the second signature-creation key out of the pair of the generated
keys in the second signature-creation key contained in the virtual-person
information file 121.

[0040]The virtual-person information management unit 111 makes an
electronic-certificate issue request to request the predetermined
authentication organization to issue an electronic certificate used for
the user terminal 30 of a third person that has acquired electronic data
from the service providing device 40 to perform an operation (a second
authentication operation) of authenticating the electronic data. The
electronic-certificate issue request contains the virtual person ID and
the second signature-authentication key. The electronic certificate
certifies that information (the virtual person ID) for identifying the
virtual person and the second signature-authentication key belong to the
virtual person. In the specification, the electronic certificate is
referred to as "virtual-person electronic certificate".

[0041]A format example of the virtual-person electronic certificate is
depicted in FIG. 4. The format example of the virtual-person electronic
certificate depicted in FIG. 4 is a standard format of a public-key
certificate in conformity to the X.509 Version 3 defined by the
International Telecommunication Union Telecommunication (ITU-T). As
depicted in FIG. 4, the virtual-person electronic certificate contains
items such as a version, a serial number, an algorithm identifier, an
issuer 310, a period of validity including a start time and a finish
time, a subject 320, an subject public-key information 330 including an
algorithm 331 and a subject public key 332, an issuer unique identifier,
a subject unique identifier, an extended area, a signature algorithm, and
a signature value 340. Main items are indicated with reference numerals
in FIG. 4.

[0042]Information set in the main items contained in the virtual-person
electronic certificate will be explained below with reference to FIG. 5.
FIG. 5 is a diagram for explaining the information set in the main items
contained in the virtual-person electronic certificate. As depicted in
FIG. 5, authentication organization information is set in the issuer 310.

[0043]The virtual person ID is set in the subject 320. If the virtual
person ID is prevented from being disclosed to a third person, it is
possible that the virtual-person management device 10 issues a code for
identifying the virtual person ID in association with the virtual person
ID and transmits the electronic-certificate issue request including the
code and the second signature-authentication key to the authentication
organization. In such a case, the virtual-person management device 10
stores the issued code in the virtual-person information file 121 in
association with the virtual person ID, and the authentication
organization issues the virtual-person electronic certificate in which
the code contained in the electronic-certificate issue request is set in
the subject 320.

[0044]Information indicating that the second authentication operation is
to be performed by the public-key encryption method or the common-key
encryption method is set in the algorithm 331 included in the subject
public-key information 330. Because the public-key encryption method is
employed as the encryption method used for generating the second
electronic signature in an example of the virtual-person electronic
certificate depicted in FIG. 5, information indicating that the second
authentication operation is to be performed by the public-key encryption
method is set in the algorithm 331. The second signature-authentication
key is set in the subject public key 332 included in the subject
public-key information 330.

[0045]An encrypted digest generated based on main information including
information containing the authentication organization information, the
virtual person ID, and the subject public-key information 330 is set in
the signature value 340. The encrypted digest is generated by the
authentication organization. Specifically, the authentication
organization hashes the main information by using a hash function thereby
generating a digest, and encrypts the generated digest with a secret key
of the authentication organization thereby generating an encrypted
digest. After acquiring the virtual-person electronic certificate, the
user terminal 30 of the third person authenticates the virtual-person
electronic certificate by using the main information and the encrypted
digest set in the signature value 340. Specifically, the user terminal 30
of the third person hashes the main information contained in the
virtual-person electronic certificate by using the hash function thereby
generating a digest, and decrypts the encrypted digest set in the
signature value 340 with a public key of the authentication organization
thereby generating a digest. The user terminal 30 of the third person
then checks the two digests. If the digests are identical to each other,
the user terminal 30 determines that the virtual-person electronic
certificate is authentic, and if the digests are not identical to each
other, the user terminal 30 determines that the virtual-person electronic
certificate is not authentic.

[0046]The virtual-person information management unit 111 calculates the
management-company responsibility-capacity evaluated value and stores the
calculated management-company responsibility-capacity evaluated value in
the management-company responsibility-capacity evaluated value contained
in the virtual-person information file 121. Specifically, for example,
the virtual-person information management unit 111 expresses credibility
based on log data about transaction in the past, a capacity for taking on
a duty based on data about a current financial ability, or the like,
continuity based on data indicating possibility of bankruptcy or a
takeover in the future, or the like, in a numeric value by using a
predetermined method and assigns the numeric value to a predetermined
evaluation calculation formula thereby calculating the management-company
responsibility-capacity evaluated value. Moreover, the virtual-person
information management unit 111 calculates the virtual-person
responsibility-capacity evaluated value and stores the calculated
virtual-person responsibility-capacity evaluated value in the
virtual-person responsibility-capacity evaluated value contained in the
virtual-person information file 121. Specifically, for example, the
virtual-person information management unit 111 expresses credibility
based on log data about transaction in the past, or the like, in a
numeric value by using a predetermined method and assigns the numeric
value to a predetermined evaluation calculation formula thereby
calculating the virtual-person responsibility-capacity evaluated value.
However, if the virtual person is initially registered, because no actual
performance of transaction has been made by the virtual person, the
virtual-person information management unit 111 temporarily calculates the
virtual-person responsibility-capacity evaluated value by, for example,
assigning the management-company responsibility-capacity evaluated value
and a user responsibility-capacity evaluated value that will be explained
later to a predetermined evaluation calculation formula.

[0047]The receiving unit 112 receives various types of information from
the user management device 20 and the user terminal 30. The information
received from the user management device 20 includes, for example, an
issue instruction for instructing issue of the virtual person ID, a first
signature-creation key issue notification to notify that a first
signature-creation key has been issued to the virtual person, and a first
authentication notification to notify that the electronic data has been
authenticated by using a first signature-authentication key. The first
signature-creation key corresponds to a secret key issued by the user
management device 20 for a user who owns a virtual person, and the first
signature-authentication key corresponds to a public key used for the
user management device 20 to authenticate the electronic data.

[0048]The information received from the user terminal 30 includes, for
example, a second electronic-signature generation request for requesting
generation of the second electronic signature for the virtual person. The
second electronic-signature generation request includes electronic data
provided by the virtual person, a first electronic signature, and the
virtual person ID. The first electronic signature is generated by the
user terminal 30. Specifically, the user terminal 30 hashes the
electronic data provided by the virtual person by using the hash function
thereby generating a digest. The user terminal 30 then encrypts the
generated digest with the first signature-creation key thereby generating
an encrypted digest. The encrypted digest corresponds to "first
electronic signature".

[0049]Upon receiving the first authentication notification notifying that
the electronic data has been authenticated by using the first
signature-authentication key, the electronic-signature generating unit
113 generates the second electronic signature. Specifically, the
electronic-signature generating unit 113 hashes the electronic data
received from the user terminal 30 by using the hash function thereby
generating a digest. The electronic-signature generating unit 113 then
acquires, by using the virtual person ID received from the user terminal
30, the second signature-creation key that is stored in association with
the virtual person ID from the virtual-person information file 121. The
electronic-signature generating unit 113 then encrypts the generated
digest with the second signature-creation key thereby generating an
encrypted digest. The encrypted digest corresponds to "second electronic
signature".

[0050]The transmitting unit 114 transmits various types of information to
the user management device 20 and the user terminal 30. The information
transmitted to the user management device 20 includes, for example, a
newly issued virtual person ID and a first authentication request
notification for requesting authentication of electronic data received
from the user terminal 30. The first authentication request notification
includes the electronic data, the first electronic signature, and the
virtual person ID. The information transmitted to the user terminal 30
includes, for example, the second electronic signature and the
virtual-person electronic certificate.

[0051]A functional configuration of the user management device 20
according to the first embodiment will be explained below with reference
to FIG. 6. FIG. 6 is a functional block diagram of the user management
device 20 according to the first embodiment. As depicted in FIG. 6, the
user management device 20 includes a control unit 21 that totally
controls the user management device 20 and a storage unit 22 in which a
program used for an operation performed by the control unit 21 and
various types of data such as a user information file 221 are stored.

[0052]The control unit 21 includes a user-information management unit 211,
a receiving unit 212, an authenticating unit 213, and a transmitting unit
214.

[0053]The user-information management unit 211 manages user information
stored in the user information file 221. Data formation of the user
information file 221 will be explained below with reference to FIG. 7.
FIG. 7 is a diagram of the data formation of the user information file
221. The user information file 221 contains, for example, a user ID, a
user responsibility-capacity evaluated value, the virtual person ID, and
the first signature-authentication key as data items. An ID for uniquely
identifying a user is stored in the user ID. A user
responsibility-capacity evaluated value for evaluating a level of a
responsibility capacity of the user is stored in the user
responsibility-capacity evaluated value. An ID for uniquely identifying a
virtual person owned by the user is stored in the virtual person ID. A
public key used for the authenticating unit 213 included in the user
management device 20 to authenticate electronic data provided to the
virtual-person management device 10 by the virtual person is stored in
the first signature-authentication key. Although the public-key
encryption method is employed as the encryption method used for
generating the first electronic signature in the first embodiment, the
encryption method is not limited to the public-key encryption method. The
common-key encryption method can be employed as the encryption method. If
the common-key encryption method is employed, a first secret key is
stored in the user information file 221 instead of the first
signature-authentication key. The first secret key stored in the user
information file 221 is used when an administrator of the user management
device 20 authenticates the electronic data provided to the service
providing device 40 by the virtual person.

[0054]The user-information management unit 211 depicted in FIG. 6 stores
the virtual person ID received from the virtual-person management device
10 in the virtual person ID contained in the user information file 221.
The user-information management unit 211 creates the first
signature-creation key (secret key) and the first
signature-authentication key (public key) as a pair of keys used for an
electronic signature for a user who owns a virtual person, and stores the
first signature-authentication key out of the pair of the generated keys
in the first signature-authentication key contained in the user
information file 221.

[0056]The receiving unit 212 receives various types of information from
the virtual-person management device 10 and the user terminal 30. The
information received from the virtual-person management device 10
includes, for example, a newly issued virtual person ID and the first
authentication request notification. The information received from the
user terminal 30 includes, for example, an issue request for requesting
issue of the virtual person ID and an issue request for requesting issue
of the first signature-creation key.

[0057]The authenticating unit 213 performs a first authentication
operation to authenticate the electronic data included in the first
authentication request notification received from the virtual-person
management device 10 and the virtual person who has provided the
electronic data. Specifically, the authenticating unit 213 hashes the
electronic data included in the first authentication request notification
by using the hash function thereby generating a digest. The
authenticating unit 213 then acquires, by using the virtual person ID
included in the first authentication request notification, the first
signature-authentication key that is stored in association with the
virtual person ID from the user information file 221. The authenticating
unit 213 then decrypts the encrypted digest included in the first
authentication request notification by using the acquired first
signature-authentication key thereby generating a digest. The
authenticating unit 213 checks the two generated digests. If the digests
are identical to each other, the authenticating unit 213 certifies that
the electronic data and the virtual person who has provided the
electronic data are authentic.

[0058]The transmitting unit 214 transmits various types of information to
the virtual-person management device 10 and the user terminal 30. The
information transmitted to the virtual-person management device 10
includes, for example, an issue instruction for instructing issue of the
virtual person ID, the first signature-creation key issue notification
notifying that the first signature-creation key has been issued to the
virtual person, and the first authentication notification notifying that
the electronic data has been authenticated. The information transmitted
to the user terminal 30 includes, for example, a newly issued virtual
person ID and the first signature-creation key.

[0059]An explanation will be given for an operation performed when a user
acquires the virtual person ID on the premise of usage of the
virtual-person management system 1 with reference to FIG. 8. FIG. 8 is a
sequence chart for explaining an operation performed when the virtual
person ID is issued. Specifically, an explanation will be given for an
operation performed when the user terminal 30 accesses the user
management device 20 that manages a user of the user terminal 30 and
acquires the virtual person ID issued by the virtual-person management
device 10 via the user management device 20.

[0065]The user-information management unit 211 included in the user
management device 20 then stores the virtual person ID received from the
virtual-person management device 10 in the virtual person ID contained in
the user information file 221 (Step S109). The transmitting unit 214
included in the user management device 20 transmits the virtual person ID
to the user terminal 30 (Step S110). Thus, the user can acquire the
virtual person ID and operate as the virtual person on the network.

[0066]A key creation operation performed by the virtual-person management
device 10 and the user management device 20 will be explained below with
reference to FIG. 9. FIG. 9 is a sequence chart for explaining the key
creation operation performed by the virtual-person management device 10
and the user management device 20. Specifically, an explanation will be
given for an operation performed when the user terminal 30 causes the
user management device 20 that manages the user of the user terminal 30
to create the first signature-creation key and the first
signature-authentication key and the user management device 20 causes the
virtual-person management device 10 to create the second
signature-creation key and the second signature-authentication key.

[0068]The user-information management unit 211 included in the user
management device 20 creates the first signature-creation key and the
first signature-authentication key (Step S202) and stores the created
first signature-authentication key in the first signature-authentication
key contained in the user information file 221 (Step S203).

[0069]The transmitting unit 214 included in the user management device 20
then transmits the created first signature-creation key to the user
terminal 30 (Step S204). Thus, the user terminal 30 can generate the
first electronic signature from the electronic data by using the first
signature-creation key received from the user management device 20.

[0070]The transmitting unit 214 included in the user management device 20
then transmits the first signature-creation key issue notification
notifying that the first signature-creation key has been issued to the
virtual-person management device 10 (Step S205).

[0071]The virtual-person information management unit 111 included in the
virtual-person management device 10 then creates the second
signature-creation key and the second signature-authentication key used
for generating an electronic signature of the electronic data provided by
the virtual person (Step S206) and stores the created second
signature-creation key in the second signature-creation key contained in
the virtual-person information file 121 (Step S207).

[0072]The virtual-person information management unit 111 included in the
virtual-person management device 10 requests the predetermined
authentication organization to issue the virtual-person electronic
certificate corresponding to the second signature-authentication key and
then acquires the virtual-person electronic certificate from the
authentication organization (Step S208).

[0073]An explanation will be given for an operation performed from when
the user terminal 30 provides the virtual-person management device 10
with the electronic data to when a third person acquires the electronic
data and authenticates the acquired electronic data with reference to
FIG. 10. FIG. 10 is a sequence chart for explaining an example of an
operation performed when the electronic data is authenticated.
Specifically, an explanation will be given for an operation performed
when a user of a user terminal B acquires the electronic data provided to
the service providing device 40 by the virtual person who is a user of
the user terminal A. In this operation, the user terminal 30 used by a
user A who has provided the electronic data is referred to as the user
terminal A, and the user terminal 30 used by a user B who has acquired
the electronic data is referred to as the user terminal B. The user
management device 20 that manages information about the user A is
referred to as a user management device A.

[0074]First, the user terminal A performs a first electronic-signature
generation operation to generate the first electronic signature from the
electronic data provided by the virtual person (Step S301). The first
electronic-signature generation operation performed by the user terminal
A will be explained in detail later.

[0075]The user terminal A transmits the second electronic-signature
generation request including the electronic data provided by the virtual
person, the generated first electronic signature, and the virtual person
ID to the virtual-person management device 10 (Step S302).

[0076]The transmitting unit 114 included in the virtual-person management
device 10 then transmits the first authentication request notification
for requesting authentication of the electronic data received from the
user terminal A to the user management device A (Step S303).

[0077]The authenticating unit 213 included in the user management device A
then performs the first authentication operation to authenticate the
electronic data included in the authentication request notification and
the virtual person who has provided the electronic data (Step S304). If
the electronic data and the virtual person are authentic, the
transmitting unit 214 included in the user management device A transmits
the first authentication notification indicating that the electronic data
is authentic to the virtual-person management device 10 (Step S305). The
first authentication operation performed by the user management device A
will be explained in detail later.

[0078]The electronic-signature generating unit 113 included in the
virtual-person management device 10 then performs a second
electronic-signature generation operation to generate the second
electronic signature from the electronic data received from the user
terminal A (Step S306). The transmitting unit 114 included in the
virtual-person management device 10 transmits the generated second
electronic signature and the virtual-person electronic certificate to the
user terminal A (Step S307). The second electronic-signature generation
operation performed by the virtual-person management device 10 will be
explained in detail later.

[0079]The user terminal A then transmits the electronic data, the second
electronic signature, and the virtual-person electronic certificate to
the service providing device 40 (Step S308). The service providing device
40 discloses the electronic data, the second electronic signature, and
the virtual-person electronic certificate received from the user terminal
A on an intermediary site for transaction of electronic data (Step S309).

[0080]The user terminal B accesses the intermediary site for transaction
(the service providing device 40) (Step S310) and then acquires the
electronic data provided by the virtual person of the user A, the second
electronic signature, and the virtual-person electronic certificate (Step
S311). The user terminal B then performs the second authentication
operation (Step S312) thereby authenticating the acquired electronic
data. The second authentication operation performed by the user terminal
B will be explained in detail later.

[0081]The first electronic-signature generation operation performed by the
user terminal A as depicted in FIG. 10 will be explained below with
reference to FIG. 11. FIG. 11 is a schematic diagram for explaining the
first electronic-signature generation operation performed by the user
terminal A as represented in FIG. 10.

[0082]As depicted in FIG. 11, the user terminal A hashes the electronic
data provided by the virtual person by using the hash function thereby
generating a digest (Step S401). The user terminal A then encrypts the
digest with the first signature-creation key thereby generating an
encrypted digest (Step S403). The encrypted digest corresponds to "first
electronic signature".

[0083]The first authentication operation performed by the user management
device A as depicted in FIG. 10 will be explained below with reference to
FIG. 12. FIG. 12 is a schematic diagram for explaining the first
authentication operation performed by the user management device A as
represented in FIG. 10.

[0084]As depicted in FIG. 12, the authenticating unit 213 included in the
user management device A hashes the electronic data included in the first
authentication request notification received from the virtual-person
management device 10 by using the hash function thereby generating a
digest (Step S501). The authenticating unit 213 included in the user
management device A then extracts, by using the virtual person ID
included in the first authentication request notification received from
the virtual-person management device 10, the first
signature-authentication key that is stored in association with the
virtual person ID from the user information file 221 thereby acquiring
the first signature-authentication key (Step S503). The authenticating
unit 213 included in the user management device A then decrypts the first
electronic signature (the encrypted digest) included in the first
authentication request notification received from the virtual-person
management device 10 with the first signature-authentication key thereby
generating a digest (Step S505).

[0085]The authenticating unit 213 included in the user management device A
checks the digest generated at Step S501 against the digest generated at
Step S505 (Step S507). If the two digests are identical to each other,
the authenticating unit 213 certifies that the electronic data and the
virtual person who has provided the electronic data are authentic.

[0086]The second electronic-signature generation operation performed by
the virtual-person management device 10 as depicted in FIG. 10 will be
explained below with reference to FIG. 13. FIG. 13 is a schematic diagram
for explaining the second electronic-signature generation operation
performed by the virtual-person management device 10 as represented in
FIG. 10.

[0087]As depicted in FIG. 13, the electronic-signature generating unit 113
included in the virtual-person management device 10 hashes the electronic
data received from the user terminal A by using the hash function thereby
generating a digest (Step S601).

[0088]The electronic-signature generating unit 113 included in the
virtual-person management device 10 then extracts, by using the virtual
person ID received from the user terminal A, the second
signature-creation key that is stored in association with the virtual
person ID from the virtual-person information file 121 thereby acquiring
the second signature-creation key (Step S603).

[0089]The electronic-signature generating unit 113 included in the
virtual-person management device 10 then encrypts the digest generated at
Step S601 with the second signature-creation key thereby generating an
encrypted digest (Step S605).

[0090]The second authentication operation performed by the user terminal B
as depicted in FIG. 10 will be explained below with reference to FIG. 14.
FIG. 14 is a schematic diagram for explaining the second authentication
operation performed by the user terminal B as represented in FIG. 10.

[0091]As depicted in FIG. 14, the user terminal B hashes the electronic
data acquired from the intermediary site for transaction (the service
providing device 40) by using the hash function thereby generating a
digest (Step S701). The user terminal B then acquires the second
signature-authentication key from the virtual-person electronic
certificate issued at Step S208 (see FIG. 9) (Step S703). The user
terminal B then decrypts the second electronic signature (the encrypted
digest) acquired from the intermediary site for transaction with the
second signature-authentication key thereby generating a digest (Step
S705).

[0092]The user terminal B then checks the digest generated at Step S701
against the digest generated at Step S705 (Step S707). If the two digest
are identical to each other, it is certified that the virtual-person
electronic certificate acquired from the intermediary site for
transaction is authentic and that the electronic data acquired from the
intermediary site for transaction is provided by the virtual person
corresponding to the virtual person ID included in the virtual-person
electronic certificate.

[0093]As described above, in the virtual-person management system 1
according to the first embodiment, it is possible to authenticate the
electronic data for the third person who has acquired the electronic data
provided by the virtual person by using the second
signature-authentication key corresponding to the second
signature-creation key issued by the virtual-person management device 10
for the virtual person, so that the first signature-authentication key
corresponding to the first signature-creation key used by the virtual
person can be concealed from the third person. Therefore, it is possible
to authenticate the electronic data provided by the virtual person
anonymously used on the network while ensuring anonymity of the virtual
person.

[0094]Although it is explained in the first embodiment that devices
managed by the management company are separately arranged as the
virtual-person management device 10 and the user management device 20,
the configuration of the devices managed by the management company is not
limited to the above. For example, functions included in the
virtual-person management device 10 and the user management device 20 can
be combined in one management device or separately arranged in a larger
number of management devices. That is, any configuration can be employed
as long as the present invention can be implemented as one virtual-person
management system.

[0095]Furthermore, although it is explained in the first embodiment that
the virtual-person management device 10 and the authentication
organization that issues the electronic certificate are separately
arranged, functions included in the virtual-person management device 10
can be combined in the authentication organization.

[0096]Moreover, although it is explained in the first embodiment that the
second signature-authentication key is created for each virtual person,
the present invention is not limited to such a configuration. For
example, it is possible that a second signature-authentication key shared
by all virtual persons is created and the second electronic signature is
generated by using the second signature-authentication key.

[0097]Furthermore, although it is explained in the first embodiment that,
as depicted in FIG. 10, the user terminal A transmits the second
electronic-signature generation request to the virtual-person management
device 10 (Step S302), and after the virtual-person management device 10
generates the second electronic signature (Step S306), the virtual-person
management device 10 transmits the second electronic signature, and the
like, to the user terminal A (Step S307) and the user terminal A
transmits the second electronic signature, and the like, to the service
providing device 40 (Step S308), the present invention is not limited to
such a configuration. For example, it is possible that the user terminal
A transmits the electronic data, and the like, to the service providing
device 40 and the service providing device 40 that has received the
electronic data, and the like, transmits the second electronic-signature
generation request to the virtual-person management device 10.

[0098]An explanation will be given for another example of the operation
performed from when the user terminal 30 provides the virtual-person
management device 10 with the electronic data to when the third person
acquires the electronic data and authenticates the acquired electronic
data with reference to FIG. 15. FIG. 15 is a sequence chart for
explaining an example of the operation performed when the electronic data
is authenticated.

[0099]As depicted in FIG. 15, the user terminal A performs the first
electronic-signature generation operation (Step S801). The user terminal
A transmits the electronic data provided by the virtual person, the
generated first electronic signature, and the virtual person ID to the
service providing device 40 (Step S802).

[0100]The service providing device 40 then transmits the second
electronic-signature generation request including the electronic data,
the first electronic signature, and the virtual person ID received from
the user terminal A to the virtual-person management device 10 (Step
S803).

[0101]The transmitting unit 114 included in the virtual-person management
device 10 then transmits the first authentication request notification to
request authentication of the electronic data received from the service
providing device 40 to the user management device A (Step S804).

[0102]The authenticating unit 213 included in the user management device A
then performs the first authentication operation (Step S805), and if the
electronic data is authentic, the transmitting unit 214 included in the
user management device A transmits the first authentication notification
indicating that the electronic data is authentic to the virtual-person
management device 10 (Step S806).

[0103]The electronic-signature generating unit 113 included in the
virtual-person management device 10 performs the second
electronic-signature generation operation (Step S807). The transmitting
unit 114 included in the virtual-person management device 10 transmits
the generated second electronic signature and the virtual-person
electronic certificate to the service providing device 40 (Step S808).

[0104]The service providing device 40 discloses the electronic data, the
second electronic signature, and the virtual-person electronic
certificate received from the virtual-person management device 10 on the
intermediary site for transaction of electronic data (Step S809).

[0105]The user terminal B accesses the intermediary site for transaction
(the service providing device 40) (Step S810) and then acquires the
electronic data provided by the virtual person of the user A, the second
electronic signature, and the virtual-person electronic certificate (Step
S811). The user terminal B then performs the second authentication
operation (Step S812) thereby authenticating the acquired electronic
signature.

[0106]The configuration of the virtual-person management device 10
according to the first embodiment as depicted in FIG. 2 and the
configuration of the user management device 20 according to the first
embodiment as depicted in FIG. 4 can be modified in various manners
without departing from the scope of the present invention. For example,
it is possible that functions of the control unit 11 included in the
virtual-person management device 10 and/or the control unit 21 included
in the user management device 20 are implemented as software and executed
by a computer so that functions similar to those of the virtual-person
management device 10 and/or the user management device 20 are achieved.
In the following description, an explanation will be given for an example
of a computer 1000 that executes an electronic-data authentication
program 1071 in which the functions of the control unit 11 and/or the
control unit 21 are implemented as software.

[0107]FIG. 16 is a block diagram of the computer 1000 that executes the
electronic-data authentication program 1071. The computer 1000 includes a
central processing unit (CPU) 1010 that executes various types of
arithmetic processing, an input device 1020 that receives data input from
a user, a monitor 1030 that displays various types of information, a
medium reading device 1040 that reads a program, or the like, from a
storage medium, a communication device 1050 that transmits and receives
data to and from a different computer via a network, a random access
memory (RAM) 1060 in which various types of information is temporarily
stored, and a hard disk drive 1070. The CPU 1010, the input device 1020,
the monitor 1030, the medium reading device 1040, the communication
device 1050, the RAM 1060, and the hard disk drive 1070 are connected to
one another via a bus 1080.

[0108]The hard disk drive 1070 stores therein the electronic-data
authentication program 1071 having functions similar to those of the
control unit 11 depicted in FIG. 2 and/or the control unit 21 depicted in
FIG. 6 and electronic-data authentication data 1072 corresponding to
various types of data stored in the storage unit 12 depicted in FIG. 2
and/or the storage unit 22 depicted in FIG. 6. It is possible that the
electronic-data authentication data 1072 is distributed as appropriate
and stored in a different computer connected to the computer 1000 via a
network.

[0109]The CPU 1010 reads the electronic-data authentication program 1071
from the hard disk drive 1070 and expands the read electronic-data
authentication program 1071 on the RAM 1060, so that the electronic-data
authentication program 1071 functions as an electronic-data
authentication process 1061. The electronic-data authentication process
1061 expands data, or the like, read from the electronic-data
authentication data 1072 on an area of the RAM 1060 that is allocated to
the electronic-data authentication process 1061 as appropriate and
executes various types of data processing based on the expanded data.

[0110]The electronic-data authentication program 1071 does not always need
to be stored in the hard disk drive 1070. It is possible that the
electronic-data authentication program 1071 stored in a storage medium
such as a compact disc read only memory (CD-ROM) is read by the computer
1000 and the read electronic-data authentication program 1071 is executed
by the computer 1000. Alternatively, it is possible that the
electronic-data authentication program 1071 is stored in a different
computer (or a server) connected to the computer 1000 via a public line,
the Internet, a local area network (LAN), a wide area network (WAN), or
the like, and is read from the different computer by the computer 1000,
and the read electronic-data authentication program 1071 is executed by
the computer 1000.

Second Embodiment

[0111]Although it is explained in the first embodiment that the public-key
encryption method using the second signature-creation key and the second
signature-authentication key is employed as the authentication method
performed between the service providing device 40 and the user terminal
30 (the user terminal B in the example depicted in FIG. 10) of the third
person, the common-key encryption method can be employed instead. In the
second embodiment, an explanation will be given for an example in which
the common-key encryption method is employed as the authentication method
performed between the service providing device 40 and the user terminal
30 of the third person.

[0112]A functional configuration of a virtual-person management device 50
according to the second embodiment will be explained below with reference
to FIG. 17. FIG. 17 is a functional block diagram of the virtual-person
management device 50 according to the second embodiment. As depicted in
FIG. 17, a control unit 51 included in the virtual-person management
device 50 is different from the control unit 11 depicted in FIG. 2 in
that a virtual-person information management unit 511 included in the
control unit 51 has a different function from that of the virtual-person
information management unit 111 included in the control unit 11.
Furthermore, the control unit 51 is different from the control unit 11
depicted in FIG. 2 in that the control unit 51 further includes an
authenticating unit 515.

[0113]The virtual-person information management unit 511 creates a second
signature common key (secret key) as a key used for an electronic
signature of the electronic data provided by the virtual person and
stores the created second signature common key in the second
signature-creation key contained in the virtual-person information file
121.

[0114]When the receiving unit 112 receives a second authentication request
notification from the user terminal 30 of the third person, the
authenticating unit 515 performs the second authentication operation and
a authentication-result notification information generation operation for
generating authentication-result notification information to notify the
user terminal 30 of a authentication result. Because the user terminal 30
of the third person may not acquire the second signature common key for
performing the second authentication operation, the user terminal 30
requests the virtual-person management device 50 to perform the second
authentication operation. The second authentication operation and the
authentication-result notification information generation operation
performed by the authenticating unit 515 will be explained in detail
later.

[0115]The virtual-person information management unit 511 included in the
virtual-person management device 50 creates a notification-information
creation key (secret key) and a notification-information authentication
key (public key) as a pair of keys used for an electronic signature of
authentication-result notification information. Furthermore, the
virtual-person information management unit 511 requests the predetermined
authentication organization to issue an electronic certificate
(hereinafter, referred to as "notification-information electronic
certificate") used for the user terminal 30 to authenticate the
authentication-result notification information.

[0116]An explanation will be given for information set in main items
contained in the virtual-person electronic certificate in a case where a
common-key encryption method is employed as the encryption method for
generating the second electronic signature with reference to FIG. 18.
FIG. 18 is a diagram for explaining the information set in the main items
contained in the virtual-person electronic certificate in the case of the
common-key encryption method. The virtual-person electronic certificate
used in the case of the common-key encryption method has the same format
as that of the virtual-person electronic certificate depicted in FIG. 5.
As depicted in FIG. 18, authentication organization information is set in
the issuer 310 and the virtual person ID is set in the subject 320 in the
same manner as in the example of the electronic certificate depicted in
FIG. 5.

[0117]Information indicating the common-key encryption method is set in
the algorithm 331 included in the subject public-key information 330.
Because the second signature common key is not allowed to be made public,
a Uniform Resource Locator (URL) for invoking the second authentication
operation is set in the subject public key 332 included in the subject
public-key information 330. When the third person accesses the URL, the
authenticating unit 515 performs the second authentication operation and
the authentication-result notification information generation operation.

[0118]An encrypted digest generated based on main information including
information containing the authentication organization information, the
virtual person ID, and the subject public-key information is set in the
signature value 340. The encrypted digest is generated by the
authentication organization. Specifically, the authentication
organization hashes the main information by using the hash function to
generate a digest and encrypts the generated digest with a secret key of
the authentication organization thereby generating an encrypted digest.

[0119]An explanation will be given for the second authentication operation
in a case where the common-key encryption method is employed as the
encryption method used for generating the second electronic signature
with reference to FIG. 19. FIG. 19 is a schematic diagram for explaining
the second authentication operation in the case of the common-key
encryption method.

[0120]As depicted in FIG. 19, the user terminal B of the third person
accesses the service providing device 40 thereby acquiring the electronic
data, the second electronic signature, and the virtual-person electronic
certificate (Step S901).

[0121]The user terminal B accesses the URL to invoke the second
authentication operation based on the virtual-person electronic
certificate (Step S902) and performs the second authentication request
notification to request the virtual-person management device 50 to
perform the second authentication operation (Step S903).

[0123]An explanation will be given for the second authentication operation
performed by the virtual-person management device 50 as depicted in FIG.
19 with reference to FIG. 20. FIG. 20 is a schematic diagram for
explaining the second authentication operation performed by the
virtual-person management device 50 depicted in FIG. 19.

[0124]As depicted in FIG. 20, the authenticating unit 515 included in the
virtual-person management device 50 hashes the electronic data included
in the second authentication request notification received from the user
terminal B by using the hash function thereby generating a digest (Step
S1001). The authenticating unit 515 included in the virtual-person
management device 50 then acquires the virtual person ID from the
virtual-person electronic certificate included in the second
authentication request notification (Step S1003). The authenticating unit
515 included in the virtual-person management device 50 then acquires the
second signature common key that is stored in association with the
virtual person ID from the virtual-person information file 121 (Step
S1005). The authenticating unit 515 included in the virtual-person
management device 50 then decrypts the second electronic signature
included in the second authentication request notification with the
second signature common key thereby generating a digest (Step S1007).

[0125]The authenticating unit 515 included in the virtual-person
management device 50 checks the digest generated at Step S1001 against
the digest generated at Step S1007 (Step S1009). If the two digests are
identical to each other, it is certified that the virtual-person
electronic certificate acquired from the intermediary site for
transaction is authentic and that the electronic data acquired from the
intermediary site for transaction is provided by the virtual person
corresponding to the virtual person ID included in the virtual-person
electronic certificate.

[0126]An explanation will be given for the authentication-result
notification information generation operation performed by the
virtual-person management device 50 depicted in FIG. 19 with reference to
FIG. 21. FIG. 21 is a schematic diagram for explaining the
authentication-result notification information generation operation
performed by the virtual-person management device 50 as depicted in FIG.
19.

[0127]As depicted in FIG. 21, after performing the second authentication
operation, the authenticating unit 515 included in the virtual-person
management device 50 hashes authentication-result notification data by
using the hash function thereby generating a digest (Step S1101). The
authentication-result notification data includes authentication data,
authentication time and date, and a second authentication result (OK or
NG). The authentication data includes the electronic data, the second
electronic signature, and the virtual person ID contained in the
virtual-person electronic certificate included in the second
authentication request notification received from the user terminal B.

[0129]The transmitting unit 114 included in the virtual-person management
device 50 transmits information including the authentication-result
notification data, the encrypted digest (the notification-information
electronic signature), and the notification-information electronic
certificate to the user terminal B (Step S1105). Thus, the user terminal
B can authenticate the authentication-result notification data received
from the virtual-person management device 50.

[0130]As described above, in the virtual-person management system 1,
because the common-key encryption method is employed as the encryption
method performed between the service providing device 40 and the user
terminal 30 of the third person, it is possible to conceal the second
signature common key used for the second authentication operation from
the third person.

[0131]It is effective to configure other embodiments by applying the
components, the representations, and arbitrary combinations of the
components of the electronic-data authentication method disclosed in the
present application to a method, an apparatus, a system, a storage
medium, a data structure, and the like.

[0132]According to the present invention, it is possible to conceal the
first signature-authentication key corresponding to the first
signature-creation key used by the virtual person from the third person.

[0133]Specifically, according to the present invention, it is possible to
achieve an effect that the electronic data provided by the virtual person
anonymously used on the network is authenticated while anonymity of the
virtual person is ensured.

[0134]All examples and conditional language recited herein are intended
for pedagogical purposes to aid the reader in understanding the invention
and the concepts contributed by the inventor to furthering the art, and
are to be construed as being without limitation to such specifically
recited examples and conditions, nor does the organization of such
examples in the specification relate to a showing of the superiority and
inferiority of the invention. Although the embodiment(s) of the present
inventions have been described in detail, it should be understood that
the various changes, substitutions, and alterations could be made hereto
without departing from the spirit and scope of the invention.